Add instructions on rebuilding the site

README.md

@@ -1,7 +1,7 @@
 # Overview
 Repo for the True North data dashboard in partnership with <a href="https://www.brabners.com">Brabners</a>.
 
-# Data pipelines
+## Data pipelines
 We use `duckdb`, `python` and `R` to pull data from [EDD](https://github.com/economic-analytics/edd/tree/main/data/parquet) (which acts as a database) and <a href="https://open-innovations.github.io/true-north/resources/">other sources</a>. This is the default and preferred option.
 
 For static datasets, we download them manually into `working`.
@@ -10,5 +10,24 @@ We track data dependencies using `dvc`.
 
 In `pipelines` we process the data sources to extract only the data we need for the site. These files are stored in data directories available to the website in `src` and checked in to GitHub. These data files drive the visualisations on the site. 
 
-# Site structure
-We use Lume to generate a static site and OI Lume charts for the visualisations.
+## Site structure
+We use Lume to generate a static site and OI Lume charts for the visualisations.
+
+## Building the site
+The site is built using the Javascript runtine `deno`, which will need to be installed. Installation instructions are available in the [Deno Runtime getting started guide](https://docs.deno.com/runtime/manual/getting_started/installation/).
+
+Once `deno` is installed, git clone the repo to the build server, and run
+
+```sh
+deno task build
+```
+
+This will create the static site assets in the `_site` directory.
+By default, this will be built with a server location as specified in the `location` option in `_config.ts`.
+This will affect the base path and any canonical URLs that are generated.
+
+It is possible to override this when generating the site by setting the `--location` flag onthe build as follows:
+
+```sh
+deno task build --location https://www.brabners.com/true-north/data-explorer/
+```